The present disclosure relates to a linear compressor.
In general, compressors are machines that receive power from a power generation device such as an electric motor or turbine to compress air, a refrigerant, or various working gases, thereby increasing in pressure. Compressors are being widely used in home appliances such as refrigerators or air conditioners or industrial fields.
Compressors may be largely classified into reciprocating compressors in which a compression space into/from which a working gas is suctioned and discharged is defined between a piston and a cylinder to allow the piston to be linearly reciprocated into the cylinder, thereby compressing a refrigerant, rotary compressors in which a compression space into/from which a working gas is suctioned or discharged is defined between a roller that eccentrically rotates and a cylinder to allow the roller to eccentrically rotate along an inner wall of the cylinder, thereby compressing a refrigerant, and scroll compressors in which a compression space into/from which is suctioned or discharged is defined between an orbiting scroll and a fixed scroll to compress a refrigerant while the orbiting scroll rotates along the fixed scroll.
In recent years, a linear compressor which is directly connected to a driving motor, in which a position is linearly reciprocated, to improve compression efficiency without mechanical losses due to movement conversion and has a simple structure is being widely developed.
The linear compressor may suction and compress a refrigerant while a piston is linearly reciprocated in a sealed shell by a linear motor and then discharge the refrigerant.
The linear motor is configured to allow a permanent magnet to be disposed between an inner stator and an outer stator. The permanent magnet may be linearly reciprocated by an electromagnetic force between the permanent magnet and the inner (or outer) stator. Also, since the permanent magnet operates in the state where the permanent magnet is connected to the piston, the permanent magnet may suction and compress the refrigerant while being linearly reciprocated within the cylinder and then discharge the refrigerant.
FIG. 1 is a partial view of a linear motor provided in a linear compressor according to a related art, and FIG. 2 is a view illustrating a state in which the linear motor is deformed after being assembled.
Referring to FIG. 1, a linear motor 1 according to the related part includes an inner stator.
In detail, the inner stator includes a first core 2 and second cores 3a and 3b coupled to both sides of the first core 2. The second cores 3a and 3b may be formed by radially stacking a plurality of core plates.
The second cores 3a and 3b include tips 6a and 6b defining outer diameters R with respect to central lines C1 of the second cores 3a and 3b, respectively. The tips 6a and 6b are disposed to face each other and to be spaced apart from each other.
The second cores 3a and 3b may be deformable by force F that acts when the plurality of core plates are assembled. Also, the second cores 3a and 3b may be more deformable by force F that acts when being assembled with the first core 2.
Particularly, the tips 6a and 6b of the second cores 3a and 3b may be spread outward by the above-described deformation of the second cores 3a and 3b, and thus, each of the second cores 3a and 3b may increase in outer diameter. That is, referring to FIG. 2, virtual lines l1 and l2 extending from outer circumferential surfaces of the second cores 3a and 3b may be inclined with respect to the central lines C1, respectively.
When each of the second cores 3a and 3b increases in outer diameter, an airgap with an outer stator (not shown) may be limited in maintenance to deteriorate operation efficiency of the motor.
The phenomenon in which each of the second cores 3a and 3b increases in outer diameter may be more intensified by the external force transferred from a predetermined component of a compressor when the linear motor is installed in the linear compressor. For example, the predetermined component may be a stator cover or frame that is coupled to one side of each of the second cores 3a and 3b. 